This invention relates to novel racemic 3-aminomethylene-6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydro-1-quinoli ne carboxylic acid, alkyl, phenyl and benzyl esters as analgesic agents, to novel racemic 3-hydroxy-methylene-6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydro-1-quin oline carboxylic acid, alkyl, phenyl and benzyl esters, useful intermediates leading to these analgesics and to the resolved dextrorotatory enantiomer 3-aminomethylene-6,7-dimethoxy-2-methyl-4-oxo-1,2,3,4-tetrahydro-1-quinoli ne carboxylic acid, ethyl ester.